hello kilereren, here you can find all search shortcuts: https://support.mozilla.org/en-US/kb/keyboard-shortcuts-perform-firefox-tasks-quickly#w_search

I tend to use F3 (find next going forward) and Shift+F3 (find previous going backwards) because many applications use these keys. However, using the Function key row does take your hands away from the center row of the keys so it may be slower until you get used to it.

There is Ctrl+G and Shift+Ctrl+G

• https://support.mozilla.org/kb/Keyboard+shortcuts
• https://support.mozilla.org/kb/Mouse+shortcuts

There's a Firefox addon called Customisable Shortcuts.

It adds an Shortcut tab to the Options window. (FF/Options/Options or Alt-Menu/Tools/Options) Under "Search", edit "Find Again" to "Alt-N", and "Find Previous" to "Alt-P". Problem solved.

[While you're at it, you can also reassign any shortcuts you tend to trigger by mistake.]

However, since some FF dev has suddenly decided to dump these longstanding shortcuts, it may be that they are clearing space to assign them to something else. You may get a clash in the future.

See also "Help > Keyboard Shortcuts"

Same problem. I really prefer to use Alt-N/P since Ctrl or Fn keys are a little far away comparatively. Actually I'm thinking to downgrade to previous version for that.